谐振式模块化直流变换器的高增益控制

High-gain Control for Resonant Modular DC/DC Converter

随着新能源发电并网系统发展和各类新兴直流负载出现,直流配电网得到快速发展,高增益直流变换器成为不同电压等级互联的关键设备。提出了一种基于子模块级联结构的谐振式模块化直流变换器RMDC(resonant modular DC converter)拓扑,并利用子模块电容与桥臂电感构成串联谐振回路实现能量传递,同时级联结构易于获得较高的电压增益。首先分析了RMDC工作原理及关键参数和电压增益之间的数学关系;在此基础上,提出一种高增益控制方法;最后通过仿真和实验结果验证了理论分析和高增益控制方法的有效性和正确性。

With the development of grid-connected power generation systems for renewable energy resources and the appearance of emerging DC loads,DC distribution network has been developed rapidly.As a result,the high-gain DC/DC converter is becoming the key equipment for the interconnection of different voltage levels.In this paper,a resonant modular DC/DC converter(RMDC)topology based on a cascade structure of sub-modules is proposed.The series resonant circuit which consists of sub-module capacitors and arm inductors is utilized to realize energy transfer.Meanwhile,the cascade structure can also obtain higher voltage gain.The working principle for RMDC is analyzed at first.Then,the mathematical relationship between the topology’s key parameters and voltage gain is derived,based on which a high-gain control method is formulated.Finally,the effectiveness and correctness of theoretical analysis and the high-gain control method were verified by simulation and experimental results.